/**
 * Copyright (C) 2013 The yydorid-framework project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.yangying.androidframework.util;

import java.util.Random;

/**
 * @author yangying
 * @date 2013-1-8 下午2:52:12
 * @version 1.0
 *
 */
public class RandomUtil {
	public static String randNum(int num){
		StringBuffer sb=new StringBuffer();
		for(int i=0;i<num;i++){
			Random r=new Random();
			int g=r.nextInt(10);
			if(g>=0 && g<10)
				sb.append(g);
			else{
				break;
			}
		}
		if(sb.length() != num)
			return null;
		return sb.toString();
	}

}
